1. Field of the Invention
The present invention relates to a cleaning tube apparatus for an endoscope which is provided with a cleaning tube which feeds liquid to a forward-end portion of an inserting section of the endoscope, to clean an observation optical system and the like.
2. Description of the Related Art
An endoscope, in which an elongated inserting section can be inserted into subject parts, such as a body cavity, and the like to observe and inspect the subject parts which cannot directly be viewed, and to treat the subject parts by the use of a treatment tool as occasion demands, has widely been used in a medical field of art, an industrial field of art and the like.
An endoscope apparatus is generally provided with cleaning means for cleaning objective lenses at forward-end portion of the endoscope whenever the objective lenses are so stained as to be incapable of satisfactorily executing observation, or the like.
Here, FIG. 1 of the attached drawings shows an example of an arrangement of a forward-end portion of an endoscope (for medical use, here) in an endoscope apparatus provided with cleaning means. The medical endoscope has an inserting section whose forward-end portion 52 is formed therein with an observation window 53. An objective lens system 54 is mounted on the observation window 53. The arrangement is such that an optical image is focused on a forward-end surface of an image guide 55 which is arranged on a focusing surface of the objective lens system 54.
A gas-feeding and liquid-feeding channel 56 is formed adjacent to the observation window 53. A cleaning nozzle 57 is mounted on a forward end of the gas-feeding and liquid-feeding channel 56. The cleaning nozzle 57 has a forward end thereof which is so arranged as to be bent to be directed or oriented toward an outer surface of the objective lens system 54 mounted on the observation window 53. The outer surface of the objective lens system 54 (observation window 53) stained by body liquid or the like can be cleaned by cleaning liquid or the like which is jetted from the nozzle 57. Further, the apparatus which cleans an objective lens by the cleaning nozzle provided adjacent to the objective lens has been disclosed in Japanese Utility Model Laid-Open No. SHO 57-187504, similarly to the above.
In the endoscope arranged as described above, however, since the nozzle 57 is bent, if the endoscope is used, filth or dirt and the like are liable to be deposited or stayed within the nozzle 57. It becomes difficult to completely remove and sterilize the dirt even by disinfection treatment due to disinfection liquid or the like, after the use. If the disinfection treatment is not perfect or complete, there may be a fear that the endoscope becomes a breeding source of various bacteria.
On the other hand, proposed in Japanese Utility Model Publication No. SHO 64-6804 is an arrangement in which a nozzle cap formed with a gas-feeding and water-feeding nozzle is detachably mounted on a forward-end portion of an endoscope, and other arrangements. By replacement of the nozzle cap to use the endoscope, it is possible to improve cleanness.
With the endoscope having the nozzle cap described above, however, there is a fear that, when gas-feeding and water-feeding pressures for cleaning are raised, the nozzle cap comes off. On the other hand, if the gas-feeding and water-feeding pressures are set low in order to prevent the nozzle cap from coming off, a problem occurs in which effective cleaning due to a sufficient hydraulic pressure cannot be executed.
Furthermore, disclosed in Japanese Patent Laid-Open No. HEI 3-272729 is an endoscope which is provided with a tube inserted in a channel and having a forward end thereof formed with a releasing bore for releasing fluid obliquely rearwardly. Also in this apparatus, cleaning fluid led into the tube is released from the releasing bore so that an objective lens can be cleaned.
With the apparatus disclosed in Japanese Patent Laid-Open No. HEI 3-272729, however, a plurality of jetting ports or openings are not peripherally provided, and there may occur a case where, if the inserting section is so operated as to be curved, the jetting openings are not oriented toward the objective lens because the cleaning tube rotates within the channel. In order to deal with this problem, means is provided for setting orientation, position and the like of the jetting openings with respect to the objective lens. This, however, causes malfunctions such that numbers of parts increase, processing steps increase and productivity is reduced, such that operability is reduced.
Moreover, as the endoscope apparatus provided with the cleaning means, there are endoscope apparatuses which are disclosed in Japanese Patent Laid-Open No. HEI 1-310638 and Japanese Patent Laid-Open No. HEI 1-192328.
In the endoscope apparatus disclosed in Japanese Patent Laid-Open No. HEI 1-310638, various lines for feeding water, for feeding gas and for sucking fluid are provided within a scope, and have respective rearward ends thereof which are connected to a water-feeding suction unit. Further, the endoscope apparatus has a control section which is operated in water feeding, gas feeding, suction and gas feeding in order with respect to an optical element at the forward end of the scope, by a single action operation, so that it is possible to easily clean the objective lens.
In the endoscope apparatus disclosed in Japanese Patent Laid-Open No. HEI 1-192328, control means is provided which always repeats intermittently one or more operations of the gas feeding, water feeding and suction during the use of the endoscope, so that it is possible to prevent dirt from flowing back to the various lines.
With the conventional apparatuses described above, however, since the lines for water-feeding, suction and gas-feeding are provided independently, an outer diameter of the inserting section of the endoscope is enlarged or increases. Furthermore, there is a fear that the suction nozzle, the suction lines and the like are clogged by dirt. Thus, disadvantages occur in which various bacteria or the like breed so as to be brought to a unclean or dirty condition, and the like.